Vascular guidewire control apparatus

ABSTRACT

A controller for use with a guidewire, such as a vascular guidewire, provides a mechanism for gripping and applying a torque to the guidewire without the need to thread the guidewire axially through the controller and at a location close to a point of access of the guidewire. In one embodiment, the controller includes a side-access, multi-part assembly including a collet or other gripping element that applies a uniform radially inward force on the guidewire. In another embodiment, for use with guidewires having active electrically controllable elements, the controller integrally or removably incorporates a switch or other mechanism to initiate an energized state. The controller thereby permits ergonomic, single-handed control of an electronically steerable guidewire, including axially displacing, torquing and steering the guidewire.

CROSS-REFERENCE TO RELATED APPLICATIONS

This patent application claims priority benefit under 35 U.S.C. §119(e)of U.S. Provisional Patent applications 60/757,443, filed Jan. 9,2006,and 60/760,511, filed Jan. 21, 2006, and as a continuation-in-part under35 U.S.C. §120 of co-pending U.S. patent applications Ser. Nos.11/090,574 and 11/090,588, filed Mar. 24, 2005 and a Continuation ofSer. No. 11/621,536 filed Jan. 9, 2007, the contents of whichprovisional and non-provisional applications are incorporated herein byreference in their entirety.

FIELD OF THE INVENTION

The present invention relates in general to the field of medical devicesand, in particular, to devices for use in interventional and diagnosticaccess, manipulation within, and negotiation of, the vascular system.

BACKGROUND OF THE INVENTION

The vascular field of medicine relates to the diagnosis, management andtreatment of diseases affecting the arteries and veins. Even whenhealthy, the anatomy of these vessels is complex, with numerousdivisions leading into progressively smaller branches. Development ofdisease within these vessels often complicates matters by altering theircaliber, flexibility, and direction. The interior, or lumen, of a bloodvessel may develop constrictions, known as stenoses, and at times mayeven be obstructed, as a result of the development of atheroscleroticplaques or by the occurrence of tears or lacerations in the vessel wall,known as dissections. These obstructions may complicate the vascularanatomy by leading to the formation of new collaterial pathways thatestablish new routes around the obstructions in order to provide bloodflow down-stream from the blockage.

In order to diagnose and treat vascular diseases, a physician may inmany instances perform a diagnostic or interventional angiogram. Anangiogram is a specialized form of X-ray imaging, requiring physicalaccess into a vessel with some form of sheath, needle or guide in orderto allow a contrast dye to be injected into the vasculature while X-raysare transmitted through the tissue to obtain an image. The contrast dyeilluminates the interior of the vessels and allows the physician toobserve the anatomy, as well as any narrowings, abnormalities orblockages within the vessels. At times, more selective angiograms areused to delineate a particular area of concern or disease with greaterclarity. Access to these more selective areas often requires theinsertion of guidewires and guide catheters into the vessels.

Vascular guidewires and guide catheters can be visualized from outsidethe body, even as they are manipulated through the body's vascularsystem, through the use of continuous low-dose fluoroscopy. Thenegotiation of the complex vascular anatomy, even when healthy, can bedifficult, time consuming and frustrating. When narrowed or obstructedby disease, the vessels are even more difficult—and sometimesimpossible—to negotiate.

Attempts to address and overcome the difficulty of negotiating vascularanatomy have led to various devices, primarily guidewires and guidecatheters, for assisting physicians. The devices vary in shape, diameterand length. In order to negotiate the smaller blood vessels as well asto provide some standardization within the industry, for example, manycatheterization systems are sized to cooperate with guidewire diametersof 0.035″ or less (0.018″ and 0.014″ being the next most common sizes).

The tips of these devices may be pre-formed into any of a variety ofshapes to help negotiate obstacles or turns within the vasculaturehaving particular geometries. For example, if the tip of a straightguidewire cannot be turned into the opening of a branch vessel, aguiding catheter with a tip having a 30 degree angle may be placedcoaxially over the guidewire and used to point the tip of the wire intothe appropriate orifice. Once the wire is in place, the catheter can beremoved and the wire advanced further until the next obstacle isencountered at which time the guiding catheter is re-advanced intoposition.

A distinct disadvantage of these pre-formed devices is a need toconstantly exchange and substitute different devices throughout theprocedure. Changing of devices generally requires either that a catheterbe withdrawn from the vasculature, while the collocated guidewireremains in position, and then be fully disengaged from the stationaryguidewire; or, alternatively, that a guidewire be removed while thecatheter remains in place, and substituted with a different guidewire.This exchange is not only time-consuming, but can also be dangerous:repetitive passage of these instruments within the vasculature caninjure a vessel wall or release an embolic particle into the bloodstreamthat could lead to stroke, loss of limb, or even death. In an attempt toaddress and overcome these problems, catheters and guidewires have beendeveloped to allow a practitioner to control, or at least to alter, thetip of the device in a more direct fashion. By means of an externalcontrol, the tip of the wire or catheter is turned, bent, flexed orcurved.

Two types of approaches are currently used to impart the control of thewire/catheter tip: (1) direct mechanical linkage and (2) shape memoryalloys (SMAs). The direct mechanical linkage approach employs actuators(e.g., wires, tubing, ribbons, etc.) that extend the full length of theguidewire/catheter. Manipulating the external, proximal portion of thecontrol actuator, displaces the distal, internal portion of the wire.Specifically, the direct mechanical linkage can be disadvantageous inthat when it is activated to deflect a guidewire's tip, it can impart astiffening, shape-altering, performance-limiting constraint on theguidewire as a whole, thereby limiting its functionality.

The SMA approach involves use of alloys that are typically of metalshaving a Nickel-Titanium component (e.g., Nitinol) that can be trainedin the manufacturing process to assume certain shapes or configurationsat specific temperatures. As the temperature of a shape memory alloychanges, the structure of the material changes between states and theshape is altered in a predetermined fashion. SMAs are used extensivelyin the medical field for a variety of purposes, e.g., stents, catheters,guidewires. Typically, the material is trained to assume a specificconfiguration on warming (e.g., stents) or to return to itspredetermined shape after deformation (e.g., Nitinol guidewires.).

If manufactured in a specific fashion, SMAs demonstrate a negativecoefficient of thermal expansion when heated and can be trained toshorten a specified amount of linear distance. By passing an electriccurrent through the material, the material's electrical resistanceproduces an increase in the material's temperature, causing it toshorten. Upon cooling, the alloy returns to its previous length. Thischaracteristic of shape memory alloys has been used to impart adeflection or alteration in the tip of a guidewire or catheter.

One approach involves an outer sheath, an inner core and several nitinolactuators disposed concentrically about the inner core. These actuatorsare controlled via an electrical connection with the core wire andconducting wires traveling in parallel with the core itself. Acontrolling device is attached at the proximal (practitioner) end of thewire. By manipulating the controlling device, such as a joystick, thedistal wire tip can be displaced in multiple directions. Anotherapproach provides an end-mounted control device, at the proximal end,having a box shape.

Another approach involves an array of microcircuits that control twonitinol actuators that slide on an eccentric board with a lowcoefficient of friction. By altering the amount of actuator that isactivated, a more or less bidirectional deflection can be imparted inthe guidewire tip. As with the previous example, this device is alsocontrolled by an end-mounted control device.

SUMMARY OF THE INVENTION

The apparatus, methods and systems according to the present invention,in their various aspects, address any of a range of problems associatedwith the manipulation of catheters and guidewires within vascularsystems during invasive diagnostic or interventional radiologicalprocedures or in other fields requiring precisely controlled penetrationof narrow passageways. Among other advantages, embodiments of thepresent invention provide controllers for variable control, steerableguidewires that may have one more of the following advantages: coaxialstructure, over-the-wire catheter compatibility, remote controllability,variably deflectable tip, low profile guidewire, controllability by adetachable, side-entry, easily positioned, single-handedly manipulated,combination torque and guidewire tip control device, ergonomiccontrollability from a position adjacent to the point of entry into thevasculature (or other passageway being accessed), and economicalmanufacturability. Aspects of the present invention also encompass orfacilitate a reduction, or minimization, of the number of guidewire orguide-catheter exchanges necessary to accomplish a designated task orprocedure, yielding an advantage not only in terms of the saving of timeand other resources, but more importantly in reducing trauma to thepassageways in which the guidewire is deployed. The combination ofguidewire and controller according to aspects of the present inventionallow convenient side-entry and single-handed repositioning of thecontroller along the length of the guidewire to allow the practitionerto manipulate the guidewire tip at any location along the guidewire,including at or near the point of entry, thereby improving ergonomics,control, efficiency, and ultimately, for medical guidewires, patientsafety.

When used in the field of interventional radiology, the apparatus,systems and methods according to the present invention provide asolution in the form of an economical, completely coaxial, variable tip,low-profile guidewire remotely controlled by a detachable, easilypositioned, single-handedly manipulated, combination torque andguidewire tip control device (controller). This device, with whichembodiments of the controller according to the present invention may beused, overcomes shortcomings of prior vascular guidewire devices whichlack the combination of a fully variable tip, a coaxial wire allowingcompatibility with other devices, and a remote control system. Its dualutilization of the outer wrapped wire as a conducting element andstructural support enables final low-profile design measurements thatpermit this system to be used with standard, currently availableover-the-wire devices (e.g., stents, angioplasty balloons, andendo-grafts). The variable and controllable nature of the guidewire tipenhances the user's ability to manipulate the guidewire throughdifficult anatomy. Therefore, it minimizes the number of guidewire orcatheter exchanges necessary to accomplish a designated task orprocedure.

In one embodiment, a vascular guidewire and control system according tothe present invention is a compact, coaxial, remotely and electricallycontrollable, variable tip guidewire that is fully exchangeable andcompatible with most interventional catheter based devices.

A controller according to another aspect of the present inventionprovides a side-entry torque device compatible with the steerableguidewire according to the present invention, permitting single-handedrepositioning of the controller along the guidewire, while reducing orminimizing trauma to the guidewire's electrical conducting wires. Inaddition to meeting criteria for the strength of the grip the controllerapplies to the guidewire, it offers several additional advantages.According to one aspect of the invention, the controller is providedwith a switch that can be operated by the user to energize the steerabletip at the distal end of the guidewire to which the controller isaffixed. This arrangement (among others according to the invention,discussed below), permits repositioning of the guidewire, by axialdisplacement, rotation and tip deflection, by the practitioner using asingle hand. According to another aspect, the controller includes afully detached collet adapted to engage with the body of the controllerand a cap of the controller in order that the collet grip the guidewirewith a uniform distribution of inwardly radial force. That is, the loadeach prong or face of the collet, of which there may be two or more,applies to the guidewire is uniformly distributed in a directionparallel to the axis of the guidewire, thereby reducing or minimizingthe possibility of damage to the guidewire in the region where it isbeing gripped by the controller.

In an embodiment of another aspect of the present invention, thecontroller can easily be attached or detached and moved freely along thesurface of the guidewire, which in turn allows a completely coaxialguidewire structure. In addition, the coaxial guidewire structurepermits its unhindered use within existing types of catheters, sheathsand vessels. In other words, the guidewire can be made to be free of anypermanent, designated attachment sites along its length. Thus, when thecontroller is removed, the guidewire has an unhindered, low-profilestate with a uniform design diameter extending from the distal guidewiretip to the proximal guidewire end. The substantially uniform diameterguidewire configuration in an embodiment of an aspect of the presentinvention enables easy exchangeability with other guidewires andcatheters, since catheters, sheaths, balloons or other devices can bereadily slid over, or removed from, the guidewire.

In an embodiment of yet another aspect of the present invention, acontroller, referred to above, comprises a combined torque and variablecontrol device, which allows precise control of a guidewire tip, whileretaining an ability to reposition and manipulate the guidewire in amechanically advantageous position near the guidewire entry site intothe sheath or catheter. As described above, the controller's easyattachment or removal at the closest possible point to the variable tipof the guidewire provides greater controllability of the tip. Anembodiment of the invention permits flexible coupling of the controllerto the guidewire, precise guidewire control, as well as a uniformdiameter, purely coaxial guidewire system.

In an embodiment of a further aspect of the present invention, aguidewire controller comprises a guidewire torque control devicecombined with a switch, preferably of ergonomic design, for energizingthe deflectable catheter tip. This combination permits the controller tobe used to torque the guidewire, and to deflect or relax the guidewiretip, single-handedly. This combined configuration allows a precisemanual guidewire control, aided by the tactile feedback of the distalguidewire tip, to help negotiate difficult anatomy or obstacles.

In an embodiment of another aspect of the present invention, acontroller for facilitating manual control by a user of a guidewirecomprises a housing having a primary axis and a first engagement featuresubstantially along the primary axis, a second engagement feature,non-parallel to the first engagement feature adapted to receive theguidewire, and a third engagement feature parallel with the firstengagement feature for accommodating a portion of the guidewire. One ormore of the engagement features may comprise slots. Furthermore, thesecond engagement feature may be perpendicular to the first engagementfeature.

The invention, in yet another embodiment, provides a switch coupled toan electrical circuit causing the flow of electricity to the tip of aguidewire, wherein the switch may be held and/or manipulated by the userin conjunction with a controller for the guidewire in a single hand.

In an embodiment of another of its aspects, the invention provides amethod of using a controller to displace, rotate, or deflect the tip ofa guidewire using a single hand, comprising the steps of aligning anon-parallel engagement feature with the guidewire so that thecontroller is in a first position, engaging the guidewire with thenon-parallel engaging feature, and shifting the controller to a secondposition in which the guidewire is fully received by the controller. Thefirst position may or may not be perpendicular to the second position.

The various aspects of the present invention can be used in concert withguidewires, energizers, switches and according to methods that are thesubject of co-pending applications entitled: Vascular Guidewire System,U.S. application Ser. No. 11/090,589; Energizer for Vascular Guidewire,U.S. application Ser. No. 11/090,588; Method for Use of VascularGuidewire, U.S. application Ser. No. 11/090,512; and Vascular GuidewireControl Apparatus, U.S. application Ser. No. 11/090,574; all filed onMar. 24, 2005, the contents of which are incorporated herein byreference in their entirety.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1A-1F show aspects of an embodiment of a guidewire according tothe present invention.

FIGS. 2A-2G show aspects of an embodiment of a guidewire controller inaccordance with the present invention.

FIGS. 3A-3D show aspects of an embodiment of a guidewire power source orenergizer according to the present invention.

FIG. 4 shows aspects of a second embodiment of a guidewire controlleraccording to the present invention.

FIGS. 5A-5C show more detail of aspects of the embodiment of thecontroller shown in FIG. 4.

FIGS. 6A-6B show a shaft, body, or housing portion of a secondembodiment of a guidewire controller according to the present invention.

FIGS. 7A-7C show a cap portion of a second embodiment of a guidewirecontroller according to the present invention.

FIGS. 8A-8C show a controller assembly in an embodiment of the presentinvention including a shaft or housing portion according to theembodiment shown in FIGS. 6A-6B, a cap portion according to theembodiment shown in FIGS. 7A-7C and a collet portion according to theembodiment shown in FIGS. 9A-9E.

FIGS. 9A-9E show a collet portion of a second embodiment of a guidewirecontroller according to the present invention.

FIGS. 10A-B show aspects of an embodiment of a controller assemblyincluding a shaft or housing portion having an engagement featureadapted to receive a guidewire along its side at a location near thepoint of entry.

FIGS. 11A-B show aspects of an embodiment of a switch used inconjunction with a guidewire controller according to the presentinvention.

DETAILED DESCRIPTION

FIGS. 1A-1F show various views of an embodiment of a guidewire 1according to the present invention. Guidewire 1, shown fragmented inFIG. 1A to permit the entirety of the guidewire to be shown in onefigure, comprises three main sections. Guidewire 1 includes an elongate,tubular structure, having a proximal end 6 (see FIG. 1F) which residesexterior to the body of a patient (or other passageway with whichguidewire 1 is being used) and physically handled by a practitioner, anda distal end, which in use will be within the passageway, having anactuator portion 2. The actuator portion 2 at a most distal portion ofthe guidewire 1 comprises a shape memory alloy (SMA) 12 or othersuitable component adapted to introduce a deflection in a tip ofguidewire 1, when activated. A third, central or mid-portion 4 ofguidewire 1 is that section of the guidewire 1 between, and coupling,the distal and proximal portions and contains an inner, centrallydisposed, electrically insulated, conductive wire 8. This wire,according to an aspect of the present invention, may be provided with agradually tapered diameter as it progresses toward the distal tip of theguidewire. In the presently illustrated embodiment, the proximal end 6of the guidewire 1 demonstrates where the inner wire 8 extends beyondthe outer wrapped wire 10 and is exposed so as to be available forelectrical connection to the controller device 46 and 150 as describedbelow and illustrated in the accompanying figures.

FIG. 1A includes a more focused view of the mid-portion 4 of theguidewire 1 in an embodiment of an aspect of the present invention. Theinner core wire 8 is a centrally disposed, electrically insulated,conductive wire having a gradually tapered diameter as it progressestoward the distal tip of the guidewire. Electrical insulation for theinner core wire 8 can be any of a variety of different suitablematerials, but, in an embodiment of this aspect of the presentinvention, the insulation is preferably provided with a very low profileto accommodate the small diameter of the guidewire 1. In one embodiment,the insulation may be of a paralyene or polyamide coating of the typeoften used in medical indications. In another, an enamel coating similarto that used on magnet-wire could be used, as could other suitablematerials.

In another aspect of the present invention, core wire 8 eventuallytapers from a cross-section dimension that almost entirely fills thelumen of the outer wrapped wire 10 near the proximal end 6 of the wireto an appreciably smaller diameter as it progresses toward the distalend. Core wire 8, however, in this embodiment, may not necessarilyextend to the most distal extent of the outer wrapped wire 10. Moreover,the full extent of the inner wire 8, its tapering characteristics andthe selection of its composition can be varied to form embodimentsexhibiting differing mechanical behavior at the tip of the guidewire 1,including but not limited to the magnitude and speed of deflection,stiffness, resiliency, and other characteristics. Some candidates forcore wire 8 include, without limitation: NiTi based wires or steelmusical wires with variable material characteristics of elasticity,resilience and ductility.

In an embodiment of one aspect of the present invention, the outerwrapped wire 10 serves dual functions. First, it provides a supportlayer which happens to be on the exterior of the guidewire 1. In thiscapacity, it provides mechanical structure sufficient for the wire toprovide pushability, torquability and flexibility for proper use. Inthis embodiment, the outer wrapped wire 10 is constructed of a singlefilament wire, capable of electrical conduction, yet insulated in asimilar fashion to the inner core wire 8. In one embodiment, thefilament is a 304v stainless steel filament with a paralyene or similarinsulating coating. In another embodiment, the filament is anapproximately 34 to 36 AWG tin or copper wire, with an enamel insulatingcover. Other suitable filaments, with or without coatings, may also beappropriate.

When in a helical configuration according to one aspect of the presentinvention, the outer wrapped wire 10 forms a tubular structure having ahollow lumen arising from its being wrapped/coiled in a tight, uniformdiameter, helical fashion. In one example, outer wrapped wire 10 issufficiently tightly coiled to possess a final maximal diameter lessthan or equal to about 0.035″. Other arrangements of the outer wrappedwire 10, whether modified helical or non-helical arrangements, or evenif tubular, woven or of other outer surface layer configuration, arealso possible and within the scope of the present invention. Regardlessof the precise wrapping configuration, the outer wrapped wire 10 in oneembodiment extends from the most distal extent of the guidewire almostto the proximal portion of the guidewire.

Secondly, the outer wrapped wire 10 in an embodiment of an aspect of thepresent invention serves as an electrical path (e.g., return) for theactuator 12. The outer wrapped wire 10 forms an electrical connectionwith the distal end of actuator 12 at the end cap 18 as described below.Being electrically insulated, as described above, outer wrapped wire 10remains electrically separated from the actuator 12 and the inner corewire 8, preventing short circuiting. At or near a proximal attachmentsite 14 of actuator 12, described below, the insulation of the outerwrapped wire 10 is selectively removed, exposing an electricallyconductive portion of this wire 10. The outer surface of this insulationcan be selectively removed in the manufacturing process by directabrasion, chemical dissolution or other suitable process. The result ofsuch process is an electrically conductive exposed surface, thatnevertheless maintains electrical separation from any inner structures.

In another embodiment, the connection points of the actuator 12 could bereversed, such that the proximal attachment site 14 connects the outerwrapped wire 10 with the proximal end of actuator 12 while the distalend of actuator 12 is connected to the inner core wire 8. The describedembodiment provides an actuator 12 that is straight when in a resting,unactuated state. This arrangement accommodates insertion and navigationof the guidewire 1 through the vasculature to a point where the sort ofprecise control enabled by the various aspects of the present inventioncan be deployed. In an alternative embodiment, not shown, that is alsowithin the scope of the present invention, the actuator 12 could be in anon-straight or flexed condition when in a resting or non-energizedstate, and then return to a straightened position as the actuator 12 isenergized by the user.

In another embodiment, shown in FIG. 1F, the guidewire 1 includes aninner core wire 8 (which, per FIGS. 1A-1C is connected at its distal endwith the actuator 12) as well as a separate inner conducting wire 11.Inner conducting wire 11 is distinct from the inner core wire 8 andconnects the proximal end of the actuator 12 to the proximal end of theouter wrapped wire 10, effectively bypassing a portion of the outerwrapped wire 10 in order to provide a decreased electrical resistancefor the guidewire and actuator assembly. At the proximal portion 6 ofthe guidewire 1, this inner conducting wire 11 may be attached (e.g.,without limitation, via soldering) or otherwise placed in direct orindirect electrical communication with the outer wrapped wire 10, suchthat a complete electrical connection can be made at the proximalportion 6 of the guidewire 1, e.g., at the proximal tip 17, via theenergizer and switch.

FIG. 1F shows the extension of inner core wire 8 beyond the mostproximal portion of the outer wrapped wire 10, in an embodiment of anaspect of the present invention. The exposed inner wire 8, with itsinsulation removed at this location, facilitates attachment of anelectrical contact 20, such as an alligator clip, of a controller(described below) in order to complete an electrical circuit for theguidewire tip actuator 12. Outer wire 10 includes insulation 9 that isremoved in a proximal. portion 11. In use, the portion labeled 13,uninsulated, would serve as an electrically negative (or positive)connection point, while the uninsulated portion of the exposed innercore wire 8, to which the reference numeral is directed in FIG. 1F,would serve as an electrically positive (or negative) connection point.

FIGS. 1B and 1C show, among other features, the variable tip portion ofthe guidewire 1 in an embodiment of the present invention. The actuator12 is a portion of the guidewire 1 that provides a mechanical force fordeflecting the distal tip 2 of the guidewire 1. In this embodiment,actuator 12 comprises a fine wire constructed of a shape memory alloy(SMA). These alloys, as discussed above, most typically consist of anickel-titanium (NiTi) based metal wire having a negative coefficient ofthermal expansion, but may consist of different alloys. When heated,these alloys may contract a certain percentage of their overall length.Being electrically conductive, but having a comparatively highelectrical resistance, they become heated when an electrical currentpasses through them and so contract linearly. When an applied current isswitched off, the alloy cools and returns to its prior length.Typically, an alloy of this sort can tolerate thousands of repeatedcontraction and expansion cycles. In addition, SMAS are available invarious diameters, lengths, surface coatings and characteristics. In oneembodiment, a guidewire actuator 12 according to the present inventioncomprises a wire of SMA having a diameter of about 0.004″. Otherdimensions are possible and may be selected for particular guidewirecharacteristics. By altering the actual length and diameter of theactuator 12, different tip deflections can be configured to meetspecific clinical situations.

FIG. 1D demonstrates an overall view of the distal tip 2 with anenlarged view of its proximal portion in an embodiment of an aspect ofthe present invention showing the actuator's proximal attachment site14. The insulation on the inner core wire 8 is removed at thisattachment site to provide an electrical contact with the actuator 12.The surface coating of the proximal actuator 12 is also removed toimprove the connection. NiTi- and possibly other SMA-based wires may bedifficult to attach via standard solder/weld methods and appear to bebest connected via a mechanical means such as crimping or tying. In anembodiment of this sort, a fine mechanical crimp may be applied toattach the actuator to the inner core wire. An alternative embodimentwould involve creating a divot in the inner core wire 8, about which theactuator 12 could be knotted. In yet another embodiment, a spot weld orconductive epoxy would fix the wire 8 at this site. Various methods forattaching actuators 12 to inner core wires 8, outer wrapped wire 10 orinner conducting wire 11, may provide a suitable a mechanical andelectrical connection between the components of the guidewire 1.

In an embodiment of another aspect of the present invention, referringagain to FIGS. 1B and 1C, the distal end of the actuator 12 ismechanically and electrically coupled at its distal attachment site 16to the outer wrapped wire 10 in an eccentric (i.e., off-center) fashion.As shown in FIG. 1B, actuator 12 progresses from a central location 15on the inner core wire 8 at its proximal attachment site 14, to aneccentric location at its distal attachment site 16 to the distal outerwrapped wire 10. This slight offset facilitates a mechanical advantageby which the actuator 12 can impart a deflection in the distal tip 2 ofthe guidewire 1. At the point of connection 16 between the outer wrappedwire 10 and the actuator 12, the insulation is removed from the outerwrapped wire to facilitate the electrical connection with the actuator12. The mechanical connection is accomplished by crimping/compressingthe actuator 12 to the outer wrapped wire 10 with the end cap 18 (shownin FIG. 1A). Alternative means of connection as listed above for theproximal attachment site could also apply to the distal attachment site.

FIGS. 2A-2G depict various views of a variable tip guidewire controlmechanism (controller) 46 in an embodiment of another aspect of thepresent invention. The illustrated embodiment of the controller 46provides a self-contained, dual purpose device capable of controllingthe deflection of the guidewire tip 2 while also serving as a torquecontroller. In addition, as described below, the controller can beplaced or repositioned anywhere along the length of the proximal end ofthe guidewire 1 to permit control of the axial progression or withdrawalof the guidewire 1. Controller 46 thus enables direct, inline,single-handed, fingertip control of the guidewire 1 at any point alongthe proximal portion of the guidewire 1 and external to the object, ormedical subject, undergoing a procedure with the guidewire 1.

FIG. 2A provides a plan view of controller 46 and FIGS. 2B and 2C-2Fside and end sectional views, which are exploded views to detail theinterior of the device. The long axis of the controller 46 runs parallelwith and is adapted to receive the guidewire 1 in a lateral fashion.When the controller 46 is in use, the guidewire 1 is seated in theguidewire channel 22. Guidewire channel 22 runs the full length of thecontroller 46 and its diameter is commensurate with the diameter of theguidewire 1 being used to permit an effective mating fit of theguidewire 1 within the controller 46, as elaborated upon below. With alatch 24 in an open position, access to the guidewire channel 22 isachieved via slot 26. This slot 26 extends the full length of thecontroller 46, with the exception of the region of a grasper swing door28. The grasper swing door 28 is mounted via hinges 30 and fastened in aclosed position by latch 24. With the guidewire 1 seated in place in theguidewire channel 22, the grasper swing door 28 can be placed in aclosed position. In the closed position, a grasper mechanism 32 isplaced firmly in contact with the guidewire 1, to permit torquing orlinearly loading the guidewire 1.

As seen in. FIG. 2G, the grasper mechanism 32 includes a set of metalprongs 34, e.g., without limitation, three in this embodiment, which maybe of any suitable material, including but not limited to copper, brass,steel or other suitable electrically conductive material (if it is toprovide an electrical connection in accordance with an aspect of theinvention in the presently illustrated embodiment). In other embodimentswhere the actuator 12 will be energized by other means, the prongs maybe of plastic, resinous or other suitable non-electrically conductivematerial. The prongs 34 may be positioned in order to circumferentiallysurround the guidewire 1 and thereby allow firm contact and grasping ofthe guidewire 1. Prongs 34 may be buttressed at their respective bases52, such that they protrude slightly into the lumen of the guidewirechannel 22. Therefore, when the grasper swing door 28 is closed, theprongs 34 are urged into contact with the guidewire 1. This arrangementserves two key functions. By firmly grasping the guidewire 1, controller46 permits a torque to be applied to the guidewire 1 surface allowingthe guidewire tip 2 to be rotated through 360 degrees in order tofacilitate negotiation of obstacles. Additionally, the positioning of agrasper mechanism prong 34 at a 12:00 position on guidewire 1facilitates an electrical connection with the exposed surface of outerwrapped wire 10. Thus, when slide switch 36 is moved forward by theuser, switch contact 38 on the switch 36 touches contact 40, which isconnected to the 12:00 grasper prong 34. The slide switch contact 38 isin electrical communication with the positive pole of battery 42 via aninsulated, flexible wire 44. The negative pole of battery 42 is thenconnected to the attachment wire 48. The attachment wire 48 then extendsfrom the controller 46 as a flexible external wire connected toattachment device 20 (such as an alligator clip). This attachment device20 may then be clipped or otherwise electrically and mechanicallycoupled to the exposed portion of inner core wire 8. The slide switch 36is therefore the means for activating the deflection of the guidewiretip 2. When slid into the forward position, slide switch 36 causes acomplete electrical connection to be set up between the battery 42 andthe actuator 12.

FIG. 2G depicts a method for operation of a guidewire 1 system in anembodiment of another aspect of the present invention. The controller46, described above, is a separate physical entity from the guidewire 1.The distal portion and then the body portion of the guidewire 1 areintroduced into the vasculature (or other passage way, for non-vascularguidewires) at a point of entry 60 in any of the standard ways known tothose familiar with these techniques. The guidewire 1 can be manipulatedby itself without the need for the control mechanism according to thepresent invention until the user reaches a point where the guidewire 1can not be further negotiated through the vasculature, either secondaryto the nature of the native anatomy or due to a diseased state such as astenosis or obstruction. At this point the user has the option of usingthe controller 46 according to the present invention. Referring to FIG.2B, the controller's connection wire 48 is first attached to the exposedportion of the inner core wire 8 via attachment 20. The user can thenattach the controller at any point along the guidewire 1 that isconvenient. As discussed above, the side entry feature of the controller46 enables a user attach and remove the controller 46 from the guidewire1 without needing to do so coaxially.

In order to attach the controller 46 to the guidewire 1, the grasperswing door 28 is unlatched and placed in the open position. Thecontroller 46 is then placed on the guidewire 1 by means of theside-entry feature provided by the slot 26. The slot 26 directs theguidewire 1 into the guidewire channel 22. The guidewire channel isformed proximal as well as distal to the grasper mechanism 32, ensuringthat the guidewire 1 is adequately supported until the grasper swingdoor 28 is closed. When the user is satisfied with the location of thecontroller, the grasper swing door 28 is closed and latched by means ofthe latch 24. The guidewire 1 is now firmly grasped in position. Whenthe user slides the switch 36 forward, the actuator is energized asdescribed above. This energized state permits current to flow to, andthrough, the actuator 2, thereby imparting a deflection on the guidewiretip 2. The degree and ultimate configuration of the deflection dependson several factors, including: the duration of activation, power sourcecharacteristics, and design considerations of the guidewire tip 2 (e.g.,the length and diameter of actuator 12 and length of inner core wire 8).

In an embodiment of another aspect of the present invention, by rotatingan attached controller 46, while simultaneously energizing the actuator12 (by moving switch 36 in an ON position), the user can manipulate theguidewire tip 2 through the anatomy or past an area of disease. The samecan be done with alternative embodiments, including such as aredescribed below. When the slide switch 36 is returned to its offposition, the actuator 12 is de-energized, allowing the guidewire tip 2to return to its original position. This procedure can be repeated forthousands of cycles. The controller 46 can easily be repositioned on theguidewire 1 by releasing the latch 24, sliding the controller to thedesired position and then re-latching the grasper swing door 28 (or asotherwise permitted by the particular mechanical design of thedetachable controller, including one or more configurations describedbelow). When it is not needed, the controller 46 can be removed entirelyfrom the guidewire 1 without difficulty.

In an alternative embodiment illustrated in FIG. 2A (shown in dashedlines) the power source 56 for the controller 46 can be housed inapparatus separate from the controller device 46.

Another aspect of the present invention concerns the profile of thedistal tip of the actuator 12, which in an embodiment of this aspect ofthe present invention is tapered. A wide variety of profiles arepossible, and may be selected among to arrive at configurations suitablefor particular design criteria for the guidewire 1. The deflectioncharacteristics of the distal end of the guidewire 1 can be altered byappropriate selection of the design parameters of the distal taperedportion of the inner core wire 8. See, for example, FIG. 1E. Narrowingthe distal taper, for example, will generally impart a tighter curveradius. This design principle according to the present invention can beused for different guidewires 1 as well as for differing uses, such asfor accessing the renal arteries versus the carotid. arteries.

A set of profile geometries that have been considered, but withoutlimitation, are set forth in the table below. Included are twopredominant cross-sectional shapes, oval and D-shaped (here,semicircular), with a listing of widths, heights (for the ovalprofiles), cross-sectional areas and lengths.

ACTUATOR TIP PROFILES CROSS- SECTIONAL WIDTH HEIGHT LENGTH AREADIMENSIONS (INCHES) (INCHES) (INCHES) (INCHES) OVAL 1 0.010 0.0039 0.253.9E−5 2 0.010 0.0039 0.5 3.9E−5 D-SHAPED/SEMICIRCULAR 1 0.008 see width0.25 2.5E−5 2 0.10 see width 0.25 3.92E−5  3 0.008 see width 0.25 2.5E−5

In accordance with an aspect of the present invention, an actuator tiphaving a D-shaped cross-sectional profile advantageously permits onsetof curvature of the tip in a preselected direction. Actuator tips havingan asymmetrical cross section have a preferential direction of curvaturewhen subjected to axial loading upon energizing of the actuator.D-shaped or semicircular cross sections tend to initiate curvatureconsistently about the flat side of the “D” or semicircle. Among otheradvantages, a profile having this general configuration will tend torepeatedly curve in the same direction, so that a user that happens tobe holding the guidewire 1 in a particular orientation need not“recalibrate” with each energizing of the actuator 2.

Many alternative embodiments of the actuator 2 are within the scope ofthe present invention. In one example, an actuator wire 12 according tothe present invention makes use of a pulley-type of mechanism, wherebyan end of the actuator 2 is attached to the inner core wire 8 as before.The insulated wire 12 is then looped around the distal end of the outerwrapped wire 10, rather than being fixed at that location. Insulatedwire 12 is then run in parallel to itself and attached more proximally54 to the outer wrapped wire 10, as shown. This arrangement enables adoubling effect of the actuator force as it shortens over a givendistance. A greater degree of force can then be used to impart differentconfigurations on the guidewire tip 2 than might be possible in otherembodiments of this aspect of the present invention.

FIGS. 2B-2F show an embodiment of a latch mechanism for controller 46according to the present invention. This embodiment involves acompressive internal latch mechanism rather than an external latch asdescribed above. This embodiment could offer improved single-handedoperation of the controller 46 and guidewire 1. The latch is engaged ina simple manner by closing and squeezing the grasper swing door 28, thatis, with guidewire 1 mounted in the controller 46. To release the latch,the door is compressed a second time, thereby releasing the hookingmechanism and allowing the grasper swing door 28 to open again.

In still another embodiment, FIG. 2G shows an integrated “all-in-one”system that does not require an external connection wire 48. Thecontroller 46 uses the outer wrapped wire 10 in a similar fashion to theembodiment described above, while a second, pointed, penetrating contactpoint 58 on the controller penetrates in-between the coils of the outerwrapped wire and makes contact with the inner core wire 8. This contactis connected to the opposite pole of the battery by a wire. This wouldallow a complete electrical circuit to occur when the slide switch 36 isactivated, thereby facilitating deflection of the guidewire tip.

Yet another embodiment of various aspects of the present invention isshown in FIG. 1D. As shown in the upper portion of FIG. 1D a fine innerconducting wire 11 is provided in coaxial location within the outer coil10, permitting the electrical return current to be transmitted with lessresistance, lowering the total power necessary to activate the actuator12 at the distal end of the guidewire 1. This electrically insulatedinner conducting wire 11 is electrically connected to the proximal endof the actuator 12 via an electrical connection that is insulated fromthe inner core wire 8. This inner conducting wire 11 tracks along thesurface of the inner core wire 8 and is electrically coupled to theproximal end of the outer coil 10. The attachment of the proximal end ofthe wire 11 to the power source (not shown) can then still be made usingthe outer coil 10 as the conducting surface. This inner conducting wire11 may be composed of a highly conductive material capable oftransmitting a current with very little drop in resistance, despite itsfine diameter. An example of this material, without limitation, would bea MP35N-DFT having a Silver core. A potentially suitable diameter,without limitation, would be in the range of 0.002″. Both of theelectrical connections of the guidewire 1 to the external power sourcecan occur at the proximal end of the guidewire 1.

Another aspect of the present invention concerns an energizer andconnection system 100 providing a mechanism for attaching the proximalportion of the guidewire 1 to a power source, the energizer 110. Inorder to obtain a completely coaxial system, the proximal portion or endof the guidewire 1 should preferably fall within design tolerances,e.g., diameter, for the remainder of the wire. This arrangement allowsfor therapeutic and diagnostic catheters and devices to be axially orcoaxially mounted over the (free) proximal end and coaxially track overor ensheathe the guidewire 10. An embodiment of this aspect of thepresent invention is shown in FIGS. 3A-3D and. FIG. 4. The proximalportion 6 of the guidewire 1 is formed of an outer wrapped wire 10,having a protruding inner core wire 8. The inner core wire 8 iselectrically insulated from the outer core wire 10. The proximal tip 17(as seen, e.g., in FIG. 1F) of the inner core wire 8 has little or noinsulation, such that it may make electrical connection with aconnection jack 120. The proximal portion of the outer wrapped wire 10also lacks insulation, such that it may also make electrical contactwith a different portion of the connection jack 120. Therefore, thesetwo distinct connection points on the guidewire are able to make anelectrical connection between the guidewire 1 and the connection jack120 in order to allow delivery and return of electrical current whilestill meeting the design requirements of a low profile, coaxial system.Thus, this embodiment of a connection system 100 according to thepresent invention still employs the essential characteristics of theguidewire 1 described above, namely using of the inner core wire 8 andthe outer coil wire 10. The inner conducting wire 11, in an embodimentof this aspect of the present invention, merely provides a moreefficient transmission of power from the distal actuator 12 to theproximal end 17 of the outer coil 10.

An embodiment of another, related aspect of the, present invention, apower source for activation of the guidewire 1 is shown in FIGS. 3A-3D.A controller 46 (or, per the description below, 150) provides improvedtactile feedback and ease of manipulation of the guidewire 1 when it isas light as possible. Therefore, housing a battery-type power sourcewithin the housing of the controller 46 itself may not be preferred,though it is within the scope of the present invention. A power sourceor energizer 110, in an embodiment of an aspect of the presentinvention, may itself be separate from the controller 46 or 150 in afashion similar to that described in the embodiment shown in FIG. 2A.The power source or energizer 110, shown in FIGS. 3A-3D, includes aconnection jack 120 to accept the positive and negative terminals of theguidewire 1, a power source in the form of one or more batteries 130,and connecting wires that couple a detachable switch on the controller46 or 150 to the power source or energizer 110.

In an embodiment of this aspect of the present invention, the connectionjack 120 of this system allows insertion of a length of the proximal end17 and a proximal portion of the guidewire 1 so that an electricalconnection can be made between the outer core wire 10 and the inner corewire 8. Other arrangements are also possible, including but not limitedto a distinct connector element adapted to mate with jack 120, butshould preferably have an external diameter not substantially greaterthan a maximal diameter of the guidewire 1. The power source orenergizer 110 also provides a means to mechanically grasp and stabilizethe proximal portion or end 17 of the guidewire 1 during use. In anembodiment of this engagement mechanism 112 according to the presentinvention, the mechanism is slidably operable with a thumb or finger toreleasably engage the proximal end or tip of the guidewire. The powersource or energizer 110 is light enough such that as the guidewire 1 isadvanced, the power source or energizer 110 is easily pulled with theguidewire 1. Or, the guidewire 1 may be looped around the power sourceor energizer 110 to build slack into the guidewire 1 and reduce orminimize the necessary movement of the power source or energizer 110.The power source or energizer may be provided with a recess or slot 124,or other suitable mechanism, for receiving a portion of the guidewire 1in order to enhance stability of the guidewire 1 during its use. Thepower source of energizer 110 may also be provided with a mechanism 114(which as shown may, but need not, be on the engagement mechanism 112)for temporarily gripping the proximal portion or end of the guidewire.The connection jack 120 also allows 360 degrees rotation of theguidewire 1 within the power source or energizer 110 to allow the user,via controller 46 or 150, to torque the guidewire 1 without limitation.The mechanical connection may occur in a variety of means includingthrough the use of an electrically conductive gripping spring, socket orlatch. This jack 120 is electrically connected to the power source orenergizer 110. Based on the anticipated power requirements, the powersource or energizer 110 may be varied. In one embodiment, two wires exitthe energizer 110 and are connected via wire(s) 122 to the switch, e.g.,26 or 160. When the switch 36 or 160 is closed, electrical current flowsfrom the battery, e.g., 130, through wire(s) 122 and the switch, e.g.,160, to the guidewire 1 with the resultant activation of the distal tip.

In another embodiment, the switch 1.60 may be configured to beattachable to the controller 150. The switch 160 may be ofcircumferential geometry, with a slot provided along one side. This slotis sized to accommodate the side-entry ability of the controller 150.The switch 160 could be placed over the guidewire 1 and then advancedonto the back end of the controller 150, where it would lock intoposition on the controller 150. When the switch 160 is not necessary foruse of the guidewire 1 during a particular procedure, the switch 160 canbe removed from the controller 46 and be placed or stored elsewhere.This removability, in this embodiment, may permit greater versatility ofuse. In various embodiments, the switch 160 may, for example,incorporate a rubberized, bladder type switch with twonear-circumferential contacts. This embodiment, shown in FIGS. 4 and5A-5C, allows a user to activate the switch 160 at any point on itscircumference, providing the user with simple, ergonomic control of theswitch 160.

In another embodiment of the switch 160, the switch 160 is notconfigured to be attachable to the controller 150. Rather, it isergonomically designed to be separate from the controller 150 and heldin the practitioner's hand in conjunction with, but separate from, thecontroller. This still allows single-handed control of the distal tip ofthe guidewire 1.

In another embodiment, shown in FIGS. 11A-B, the switch can be designedto sit in the user's hand while being held by, for example, just thefourth and fifth fingers, or even a single finger. According to thisembodiment, the switch may be composed of a polymer or elastic materialknown or used in the art, and may consist of two halves or portions asshown in FIG. 11B. Furthermore, as shown in FIG. 11A, the switch mayhave a curved surface 610 adapted for the contour of the user's fingersgripping the switch, and a related, convex surface 620 accommodated forthe palm or portion of the user's hand adjacent to the fingers holdingthe switch. Thus, use of the fourth and fifth fingers to hold the switchaccording to this embodiment may include using part of the user's handor palm as well. The switch may be activated by squeezing one or both ofthe surfaces 610 and 620 of the switch when it is placed in the user'shand as described above. Embedded electronics, not shown in theseFigures, may be used to help accomplish such activation. These featuresof the switch allow the user to maintain simple, ergonomic control ofthe switch and single-handed control of the distal tip of the guidewire1. In this embodiment, the switch may be separate from the controller150, but used in conjunction with the controller 150 in a single handedfashion. Furthermore, the switch may be connected to energizer 110 byeither a wired or wireless connection.

Another embodiment of the controller 150 according to the presentinvention is shown in FIGS. 4 and 5A-5C. This embodiment employs aside-entry slot mechanism; like the embodiment described above. Ratherthan the latch type closing mechanism disclosed in that example,however, this embodiment employs a screw-down collet configuration,which may permit a mechanical advantage relative to the illustratedlatch-type mechanism. The controller 46 in this embodiment includesthree components. The first, shown in FIGS. 6A and 6B, is a housing,body or shaft 200 having an inner lumen 210 and a side slot 220 alongits length. The slot 220 allows for side-entry of the guidewire 1 intothe shaft lumen 210. The distal end 230 of the shaft 200 is providedwith external screw-threads 240 for adequate mechanical advantage whenengaging a mating, internally threaded cap 300 having mating threads310. The shaft 200 may be formed of any number of suitable materialsincluding, without limitation, nylon-based, high grade medical plasticshaving a comparatively stiff modulus of elasticity.

According to embodiments of aspects of the present invention, thecontroller 150 is provided with an engagement feature for enabling, orat least facilitating engagement of the guidewire 1 by the controller150 using one hand only. In one embodiment, the single handed engagementfeature is an engagement slot that is non-parallel to a primaryreceiving feature (e.g. slot 220) of the controller 150. FIG. 10Brepresents one possible depiction of this embodiment of an aspect of theinvention, in which the engagement slot 540 is substantiallyperpendicular to the primary receiving slot 520. This depletionrepresents only one way of achieving the single handed engagementfeature of the controller 150, as other arrangements of the engagementslot 540 and primary receiving slot 520 may also be utilized.

The side-entry slot mechanism or single handed engagement feature inthis embodiment of the controller 150, or in the embodiments describedabove, may consist of a slot having three portions: a primary slot 520parallel to the axis of the controller, a second, engagement slot 540,which may be non-parallel to the primary slot 520, for engaging theguidewire, and a third slot 560, parallel with the primary slot 520 andthe controller 150, for accommodating a portion of the guidewire 1. Asshown in FIG. 10, the primary slot 520 may receive a length of theguidewire 1 similar to slot 26 or 220 in the embodiments above. Theengagement slot 540, perpendicular to the primary slot 520 in thisillustrated embodiment, is continuous with the primary slot 520 and issimilarly adapted to align with and receive a guidewire 1. Together,these portions of the slot may engage the guidewire 1. Using a singlehand, the practitioner can first orient the controller 150 non-parallelto the guidewire 1 and place the engagement slot 540 over the side ofthe guidewire 1. Subsequently, the practitioner can align the primaryelongate slot 520 such that it can slide over and finally sit on theguidewire 1. The practitioner may, during this procedure, maintaincontrol of the guidewire 1 with the other hand, which remains freeduring engagement of the controller 150. The engagement slot 540 mayfunction as a fulcrum that facilitates the act of aligning the primaryslot 520 over the guidewire 1 and locking the controller 150 onto theguidewire 1. The “L” shape of the slot in this particular embodimentallows the practitioner to achieve such alignment and repositioning ofthe controller 150 in an efficient, single handed manner Furthermore,the advantages of side entry and removal with respect to the guidewireare preserved.

The second component of the controller 150 is a collet 400, shown inFIGS. 8A-8C and 9A-9C. The collet 400 is configured to slide in an axialfashion within the lumen 210 of the shaft 200. The collet 400 is alsoprovided with a side slot 420 to allow the guidewire 1 to pass withinits lumen 410. On the opposite side of the slot 220 of shaft 200 is aspline 250 that fits within a groove on the inner surface of the shaft200. Therefore, when the collet 400 is within the shaft 200, the collet400 will not rotate, but will maintain an alignment of the slots 420 and220, respectively, of the collet 400 and the shaft 200. The distal end430 of the collet 400 includes at least two prongs. In the illustratedembodiment, but without limitation, the prongs 442, 444, 446, 448, ofwhich there are 4, are formed as part of the collet 400, which slideswithin the lumen 210 of the shaft or housing 200. Therefore, as the cap300 is tightened, it compresses the prongs 442, 444, 446, 448 on thefront end radially inwardly toward the guidewire 1 in order to grip it.The cap 300 also drives the sliding collet 400 into the shaft 200 as itis tightened. The distal or leading end 230 of the shaft or housing 200is provided with a reverse bevel 235 so that, as the collet 400 isdriven into the shaft 200, the prongs 442, 444, 446, 448, which areprovided with respective complementary bevels 437 at their proximal end,are also compressed by this bevel 235 of the shaft or housing 200. Thisbevel arrangement increases the mechanical advantage of the collet 200and also allows the prongs 442, 444, 446, 448 to grip the guidewire 1with a more evenly distributed gripping surface—rather than beinggripped at only one point, which can rotate the prongs and cause them toimpart undue and damaging point stresses on the guidewire 1 or itscomponents. Distribution of the prongs 442, 444, 446, 448 around thelumen 410 permits their compression to impart a grip on the guidewire 1when the cap 300 is tightened to engage the bevels 350 of the cap 300and shaft 200 with the complementary bevels of the prongs 435 of thecollet 400. A gripping surface 470 on each prong 442, 444, 446, 448 maybe curved, concavely with respect to the guidewire 1, to disperse thecompression forces of the respective prong 442, 444, 446, 448 along thesurface of the guidewire 1. This dispersion reduces or eliminates afocused, high-pressure contact that could potentially damage underlyingelectrical components of the guidewire 1. Further, the shaft in thisembodiment incorporates a means to lock the removable switch 160 inplace.

A third component of the controller 150 is the cap 300, shown in FIGS.5A, 7A-7C and 8A-8C As shown in FIGS. 8A-8C, the cap 300 mates with theshaft 200. Inner threads 310 of the cap 300 allow for longitudinalmotion of the cap 300 along the shaft 200. The cap 300 also is providedwith a slot 320 that is aligned with the shaft slot 220 and collet slot420 during insertion and removal of the guidewire 1. As the cap 300 istightened, the inner bevel 350 of the cap 300 compresses the prongs 442,444, 446, 448 of the collet 400 down and onto the guidewire 1.Furthermore, as the collet 400 is driven into the shaft 200, theproximal bevel 437 of the collet prongs 442, 444, 446, 448 abuttingbevel 235 of the shaft 200 provide additional mechanical advantage tocompress the prongs onto the guidewire 1. The cap 300 is constructed ofany suitable material having a sufficiently stiff modulus of elasticityin order to prevent outward deflection of the cap 300 as it is tightenedon the shaft 200.

The outer configuration of the shaft 200 incorporates a proximal taperedend that allows for advancement of the switch 160 from the back end andonto the controller 150. The switch 160 may snap into position (engagingwith means 260) when desired.

An additional embodiment of the switch and connection system accordingto an aspect of the present invention may utilize a wireless system. Inthis wireless embodiment a transmitter within the switch is configuredto transmit a signal to the power source or energizer 110 at theproximal end of the guidewire 1. When the power source or energizer 110receives the signal, a circuit is closed within the power source orenergizer 110, thereby allowing deflection to occur at the distal end ofthe guidewire 1. This wireless embodiment may incorporate a small scalewireless device, such as (but not limited to) a Zigbee or Bluetoothwireless protocol system, which permits the system to be implementedwithin the design constraints of the switch and connection system.

The various aspects of the present invention not only permit the use ofa steerable or controllable guidewire having advantages over previoussystems, but also allow the guidewire to be controlled at or near thepoint-of-access into the vasculature. The present invention also enableson-the-wire control while leaving the proximal end of the guidewire 1 tobe selectably and easily freed to permit coaxial loading of otherinterventional radiology devices on the guidewire 1 (e.g., catheters,angioplasty balloons and other devices).

The various apparatuses and methods according to the present invention,and the principles that make them possible, may be applied in any fieldsrequiring a steerable guidewire. Such fields include not only thevascular field of medicine, but also additional medical fieldsincluding, but not limited to, urology, general surgery and gynecology.Furthermore, these principles could also be applied to areas outside themedical field, such as veterinary medicine, inspection, mining,telecommunications (e.g., conduit), water distribution, security,national defense, electrical, entertainment and other systems.

While the various aspects of the present invention have been shown anddescribed with reference to particular embodiments, persons skilled inthe art will understand that various changes in form and details may bemade without departing from the spirit and scope of the invention as setforth in the appended claims. The many details and specifics should notbe construed as limitations on the scope of the invention as claimed,but rather as exemplifications, and the scope of the invention should bedetermined not by these illustrated embodiment(s), but rather-by theappended claims and their legal equivalents.

1. An apparatus for use in interventional or diagnostic access to avascular system, said apparatus comprising: a guidewire having anelectrically operable actuator at a distal end portion of saidguidewire, an inner wire which is connected with a first end portion ofsaid actuator, and an outer wire which is connected with a second endportion of said actuator, said outer wire has a plurality of turns whichextend around said inner wire and are electrically insulated from saidinner wire; and a manually engageable guidewire controller to whichforce can be done manually applied to transmit torque to said guidewireto rotate said guidewire about a longitudinal central axis of saidguidewire and to which force can be manually applied move said guidewirealong the longitudinal central axis of said guidewire, said controllerengages at least one turn of said plurality of turns of said outer wireto enable electrical current to be conducted between said outer wire andsaid controller and to enable force to be transmitted from saidcontroller to said outer wire, said controller includes a switch whichis manually actuatable between an on condition in which a flow ofelectrical current is conducted between said controller and said outerwire to effect operation of said actuator and an off condition in whichthe flow of electrical current between said controller and said actuatoris interrupted.
 2. An apparatus as set forth in claim 1 wherein saidactuator is at least partially formed of a shape memory alloy having anegative coefficient of thermal expansion, said plurality of turns ofsaid outer wire enclose said actuator.
 3. An apparatus as set forth inclaim 1 wherein said controller includes a channel which receives aportion of said outer wire and a portion of said inner wire, saidcontroller having a door which is movable between an open condition inwhich a slot is open to enable said portion of said outer wire and saidportion of said inner wire to be positioned in said channel and a closedcondition in which said portion of said outer wire is gripped by saidcontroller and said portion of said inner wire is disposed in saidchannel.
 4. An apparatus as set forth in claim 3 wherein at least oneprong extends into said channel and contacts at least one turn of saidouter wire when said door is in the closed condition.